A single line in a New Yorker article has turned into an outsized political liability for the Obama administration.

Back in April, when the Arab Spring was in full bloom and the administration was trying to cope with the implications, journalist Ryan Lizza came out with a story about President Obama’s foreign policy. The headline was “The Consequentialist,” and the gist, or at least part of the gist, was that the president was dealing with the issues as they came up, instead of seeking to establish some kind of doctrine.

But in a piece that ran 9,200 words, there was one sentence that stuck like no other, and that continues to live on: “One of [Obama’s] advisers described the President’s actions in Libya as ‘leading from behind,’ ” Lizza wrote.

It was an anonymous quote from an official who may or may not have been in the White House, but conservatives seized on it, citing the remark as evidence that Obama’s foreign policy would undermine American strength and diminish its presence on the world stage.

Weeks later, rather than fading away, “leading from behind” has become the rallying cry of Republican presidential candidates intent on attacking the president’s leadership style and his approach to foreign policy.

“We need a president who fully understands that America never leads from behind,” former Minnesota governor Tim Pawlenty told the Council on Foreign Relations.

“We can’t afford four more years of a president who is not leading in this nation or leading abroad. We can’t afford four more years of a president, who in his own words said, when it came to foreign policy, he was going to lead from behind,” Rep. Michele Bachmann (R-Minn.) said at a rally last week in Iowa. “When is the last time you heard an American president say he is going to lead from behind?”

The quote came from an unnamed aide, however, not from Obama. And, it’s not exactly how the administration would describe his foreign policy.

Indeed, even before the New Yorker article came out, administration officials tried to explain that, while the president’s leadership style on foreign policy might not reflect that of his predecessor, it was leadership of a different kind.

“This is the Obama conception of the U.S. role in the world -- to work through multilateral organizations and bilateral relationships to make sure that the steps we are taking are amplified,” Ben Rhodes, the deputy national security adviser for strategic communications, told The Post in March. “Maybe this is a different conception of U.S. leadership. But we believe leadership should galvanize an international response, not rely on a unilateral U.S. response.”

Shortly after the publication of the New Yorker story, national security adviser Thomas E. Donilon was asked by Fareed Zakaria of CNN whether “leading from behind” characterized Obama’s policy. Answer: not at all.

“We have from the outset, as I described earlier, undertaken a very serious effort to rebalance America’s look and activities in the world,” Donilon said.

He said that the president had time and again made tough decisions and shown true leadership – from devoting more resources to Afghanistan, to drawing down in Iraq, to taking a lead in the G-20. “The entire effort here is to have America restore its influence, power and authority in the world,” he said.

According to Donilon, the “rebalancing” of U.S. foreign policy has been about “renewing alliances both in Asia and in Europe; engaging in positive, constructive relationships through purposeful work with great powers as a platform from which we can operate; engaging and developing deeper relationships with emerging powers like India, Brazil and others; and rebalancing our efforts in the world, which is an absolutely critical thing for us to pursue.”

Whatever one might think of that foreign policy, it is not the simplest one to articulate at a campaign rally. And for that, perhaps, Republicans can be grateful.